The U.S. Preventive Services Task Force (USPSTF) and the Healthy People 2000 reports call for primary care physicians to adopt a new paradigm of clinical preventive practice. Previous research has documented a relatively weak performance in actual delivery of many preventive services. Limitations of prior work include a poorly detailed understanding of the competing demands of primary care practice and potentially inaccurate methods for measuring the delivery of preventive services, particularly counseling. The proposed study will examine the practices of 120 family physician members of the Research Association of Practicing Physicians (RAPP). Four study teams of two nurse-researchers each will evaluate the provision of care to consecutive patients during two separate days at each of the study practices. Chart audit and patient exit questionnaires will be used to measure the baseline prevalence of preventive services delivered, and the eligibility for additional services by USPSTF age-gender specific recommendations. The incidence of delivery of preventive services will be assessed with direct observation of the medical encounter. In addition, the Davis Observation Code will be used to characterize the time spent on various activities during the medical encounter. Other potential determinants of preventive service delivery to be examined will include characteristics of physicians, patients, the medical encounter, and the office environment. Descriptive analyses will profile the time spent in the different activities of the medical encounter. The level of delivery of USPSTF- recommended preventive services will be determined for individual services and for the aggregate categories of counseling, screening, immunization, and chemoprophylaxis services. In addition, the concordance of medical record review, patient exit questionnaire, and physician questionnaire about usual practices, will be compared with direct observation measures for individual and aggregate categories of preventive services. Finally, characteristics of the medical encounter, physician, patient and the practice environment, that are associated with preventive service delivery will be assessed. Content analysis of data from brief ethnographic observations and modified focus groups of the nurse observers will enhance interpretation of study findings and enlighten the development of new hypotheses about ways to increase preventive service delivery. The proposed study will provide previously unavailable data about delivery of preventive services, particularly counseling services, by physicians within the competing demands of the medical encounter. Data on how time is actually spent during the medical encounter will be useful for efforts to implement practice guidelines and to determine how well payment systems, such as the new RBRVS-based Medicare system, reflect actual practice. The study will provide a unique base of information from which to develop innovative new methods to increase preventive service delivery by primary care physicians.